This invention relates to holograms and particularly to methods for recording and reconstructing multicolor focused image holograms.
U.S. Pat. Nos. 3,535,012 and 3,535,013 describe the recording of holograms by focusing an image of an object at or near the plane of the holographic recording material. The image is reconstructed at or near the plane of the hologram. Such holograms do not require highly monochromatic reconstruction beams such as those available from lasers. Rather, images may be reconstructed with "quasi monochromatic" light from an ordinary white light source.
Multi-color holograms of this type may be recorded with separate red, green, and blue illuminating beams. However, since separate red, green, and blue images are recorded on the holograms in the form of interference fringes, reconstruction of the hologram by multi-color beams produces color images but also produces cross-talk images. For example, a red reconstruction beam reconstructs not only the red image but also two red colored cross-talk images from the recorded green and blue colors. There are two cross-talk images for each color, a total of six cross-talk images are reconstructed. These cross talk images overlap the real reconstructed images, blur them, and deteriorate the color reproduction.
An object of the present invention is to improve the recording and reconstruction of multi-color holograms.
Another object of the invention is to minimize or remove the cross-talk images.
Another object of the invention is to enlarge the observation zone of the real image.